I don't think new UI for dev.twitter.com will be better. Because Old one's background color was pleasant and clean. That was the theme of twitter. But in new UI dark blue color is somewhat annoying. I think twitter should revert back to old UI itself.

In old UI navigation was easier. For example now i'm in upload image doc, it'll show all other upload api endpoints methods in the leftpane. but in new UI it's not showing like that. There's a lot of UI breakages in new one.

And old one's color was pleasant left pane with 'summer sky' (#25AAE2) color for texts, it looked cool. But in new UI dark blue color texts on the background is somewhat makes me feel uncomfortable. And top bar with slim blue gradient is also not seems good.

I feel 'Summer sky' (#25AAE2) color is twitter's brand color, but that is missing in new UI and overridden by dark blue color.

Thanks for this feedback, we'll be sure to pass it along to the design team.

Apologies for the layout issues, particularly with the media upload documentation (that's something I am responsible for, and will fix). With such a large quantity of content that we've ported to the new stack, there are a number of places where we've got some broken markup, and we are working on this now. Do keep letting us know when and where you see issues, we need the help to make things better!